| Summary: | 碩士 === 國立雲林科技大學 === 化學工程與材料工程系 === 105 === The purpose of this study is to prepare cardanol-based polyurethanes networks, using two steps method for the synthesis of polyurethane. That is, the use of the aliphatic isocyanate 4,4’-Methylenebis(cyclohexyl isocyanate) (H12MDI) as a hard segment and polyethylene glycol (PEG) molecular weight of 1000 or 2000 as a soft segment synthetic polyurethane prepolymer, and then use the agricultural renewable resources of the material of the cardanol for the monohydroxyphenol ortho with a 15 carbon long carbon chain, and modified into a polyhydroxy functional group of cardanol-based as a chain extender for condensation polymerization, the thermal properties and mechanical properties of the films were investigated. The cardanol-based have been characterized by fourier transform infrared sepectromter, solid-state nuclear magnetic resonance spectrometer and and the molecular weight and hydroxyl functional groups were determined using gel permeation chromatographyer. The reactivity test of the hard segment, the soft segment and the chain extender was determined using a differential scanning calorimeter. The cardanol-based polyurethanes were identified by FT-IR. The thermal properties of the films were analyzed by theromgravimetric analysis and DSC. In the mechanical properties of the universal tensile testing machine that the tensile strength and elongation at break.
The results of FT-IR,1H-NMR and 13C-NMR were used to identify the cardanol-based. The n value of the cardanol-based is 5.24. The OH number of the reactive functional group was 7.24. The cardanol-based was added as a chain extender to the polyurethane prepolymer to synthesize the cardanol-based polyurethane networks. Identification by FT-IR is successful. The increase in the molecular weight of the polyol with cardanol-based polyurethanes was found by TGA and DSC with high thermal stability, and the glass transition temperature moves to a low temperature. In the mechanical properties analysis, the tensile strength of the cardanol-based polyurethanes decreased with the increase of the molecular weight of polyethylene glycol but the elongation at break increases. In the gel fraction analysis,the cardanol-based polyurethanes are better than commercial polyurethanes.
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